ORAU TEAM

Dose Reconstruction

Project for NIOSH

Oak Ridge Associated Universities I Dade Moeller & Associates I MJW Corporation

Page 1 of 35

Document Title:

Parameters to Consider When Processing 

Claims for Construction Trade Workers

Document Number: ORAUT-OTIB-0052

Revision: 00

Effective Date: 08/31/2006

Type of Document: OTIB

Supersedes: None

Subject Experts: Melton H. Chew, John A. Devanney, Leo G. Faust, Robert L. Morris, and 

Eugene W. Potter

Document Owner

Approval: Signature on File Approval Date: 08/28/2006

John M. Byrne, Task 3 Manager

Concurrence: Signature on File Concurrence Date: 08/28/2006

Edward F. Maher, Task 5 Manager

Concurrence: Signature on File Concurrence Date: 08/29/2006

Kate Kimpan, Project Director

Approval: Signature on File Approval Date: 08/31/2006

James W. Neton, Associate Director for Science

 New Total Rewrite Revision Page Change

FOR DOCUMENTS MARKED AS A TOTAL REWRITE, REVISION, OR PAGE CHANGE, REPLACE THE PRIOR 

REVISION AND DISCARD / DESTROY ALL COPIES OF THE PRIOR REVISION.
Document No. ORAUT-OTIB-0052 Revision No. 00 Effective Date: 08/31/2006 Page 2 of 35

PUBLICATION RECORD

EFFECTIVE 

DATE

REVISION 

NUMBER DESCRIPTION

08/31/2006 00 First approved issue. New document to describe the parameters to 

consider when processing claims for CTWs. Incorporates formal 

internal review comments and comments from the Worker Outreach 

meetings with the Hanford PACE Local (Steelworkers and Guards) 

on 05/22/2005 and the Central Washington Building and 

Construction Trades Council on 01/15/2005. Revised to incorporate 

additional NIOSH comments. There is an increase in assigned dose 

and a PER is required. Training required: As determined by the 

Task Manager. Initiated by Melton H. Chew and John A. Devanney.
Document No. ORAUT-OTIB-0052 Revision No. 00 Effective Date: 08/31/2006 Page 3 of 35

TABLE OF CONTENTS

SECTION TITLE

Executive Summary............................................................................................................................. 5

PAGE

1.0 Introduction................................................................................................................................. 6

2.0 Purpose ...................................................................................................................................... 7

3.0 Scope ......................................................................................................................................... 7

4.0 Sources of Data .......................................................................................................................... 8

4.1 General Description of External Dose Data.......................................................................... 8

4.2 General Description of the Adjustment Factor...................................................................... 8

4.3 General Description of Bioassay Data Used for Internal Dose ............................................. 8

4.4 General Description of Non-Penetrating Dose Data............................................................. 9

5.0 Comparison of CTW and AMW Doses ........................................................................................ 9

5.1 SRS Penetrating Dose Comparison..................................................................................... 9

5.2 SRS Internal Dose Comparison.........................................................................................11

5.3 SRS Non-Penetrating Dose Comparison ...........................................................................12

5.4 Rocky Flats Penetrating Dose Comparison........................................................................12

5.5 Rocky Flats Internal Dose Comparison..............................................................................13

5.6 Rocky Flats Non-Penetrating Dose Comparison................................................................16

5.7 Y-12 Penetrating Dose Comparison...................................................................................17

5.8 Y-12 Internal Dose Comparison.........................................................................................18

5.9 K-25 Penetrating Dose Comparison...................................................................................20

5.10 K-25 Internal Dose Comparison.........................................................................................20

5.11 ORNL Penetrating Dose Comparison ................................................................................22

5.12 ORNL Internal Dose Comparison ......................................................................................23

5.13 INL Penetrating Dose Comparison ....................................................................................26

5.14 INL Internal and Non-Penetrating Dose Comparison .........................................................27

6.0 Hanford Site..............................................................................................................................27

6.1 Hanford Site Penetrating Dose Comparison ......................................................................27

6.2 Hanford Site Internal Dose Comparison.............................................................................28

7.0 Conclusions ..............................................................................................................................31

7.1 Prescribed External Adjustment Factor for All DOE Facilities............................................. 31

8.0 Limitations and Applications...................................................................................................... 32

8.1 Limitations .........................................................................................................................32

8.2 Guidance on the Determination of Penetrating Dose for Unmonitored CTWs .................... 32

8.3 Guidance on the Determination of Non-Penetrating Dose for Unmonitored CTWs............. 32

8.4 Guidance on the Determination of Internal Dose................................................................33

8.5 Guidance on the Determination of Occupational Medical Dose.......................................... 33

References ........................................................................................................................................34
Document No. ORAUT-OTIB-0052 Revision No. 00 Effective Date: 08/31/2006 Page 4 of 35

LIST OF TABLES

TABLE TITLE

5-1 Observed ratios for SRS ........................................................................................................

PAGE

10

5-2 Observed ratios for Rocky Flats ............................................................................................. 13

5-3 Observed ratios for ORNL...................................................................................................... 23

5-4 Observed ratios for INL .......................................................................................................... 27

6-1 Observed ratios and average penetrating dose for CTWs and AMWs at Hanford .................. 30

LIST OF FIGURES

FIGURE TITLE

5-1 95th-percentile annual penetrating dose for CTWs and AMWs for the DOE complex...............

PAGE

9

5-2 95th-percentile penetrating dose for SRS............................................................................... 10

5-3 Results of bioassay samples above the reporting level for randomly selected CTWs 

and non-CTWs at SRS........................................................................................................... 11

5-4 95th-percentile non-penetrating dose for SRS........................................................................ 12

5-5 95th-percentile penetrating dose for Rocky Flats ................................................................... 13

5-6 50th-percentile plutonium in urine for Rocky Flats.................................................................. 15

5-7 84th-percentile plutonium in urine for Rocky Flats.................................................................. 16

5-8 95th-percentile non-penetrating dose for Rocky Flats ............................................................ 17

5-9 95th-percentile penetrating dose for Y-12 .............................................................................. 18

5-10 50th-percentile uranium in urine for Y-12 ............................................................................... 19

5-11 84th-percentile uranium in urine for Y-12 ............................................................................... 19

5-12 95th-percentile penetrating dose for K-25 .............................................................................. 20

5-13 50th-percentile uranium in urine for K-25 ............................................................................... 21

5-14 84th-percentile uranium in urine for K-25 ............................................................................... 21

5-15 95th-percentile penetrating dose for ORNL ............................................................................ 22

5-16 50th-percentile plutonium in urine for ORNL........................................................................... 24

5-17 84th-percentile plutonium in urine for ORNL........................................................................... 24

5-18 50th-percentile uranium in urine for ORNL ............................................................................. 25

5-19 84th-percentile uranium in urine for ORNL ............................................................................. 25

5-20 Mean value for penetrating dose for INL ................................................................................ 26

6-1 Average annual penetrating dose for Hanford........................................................................ 29

6-2 50th-percentile for Pu-239 in urine for Hanford....................................................................... 30

6-3 84th-percentile for Pu-239 in urine for Hanford....................................................................... 31
Document No. ORAUT-OTIB-0052 Revision No. 00 Effective Date: 08/31/2006 Page 5 of 35

EXECUTIVE SUMMARY

This document provides guidance for performing dose reconstructions for unmonitored construction 

trade workers (CTWs). 

An investigation of the Department of Energy (DOE) complex was conducted to determine the ratio of 

the external and internal annual doses received by CTWs to those received by all other monitored 

workers (AMWs). In general, it was found that for the DOE complex the internal and external annual 

doses received by the CTWs were usually bounded by those received by the AMWs. Examination of 

the individual DOE sites indicated that in some instances, at some sites, the external annual doses 

received by the CTWs exceeded those of AMWs. In these instances, the observed ratios of CTWs to 

AMWs external doses were further examined. This resulted in the development of a favorable to 

claimant adjustment factor of 1.4, which will be applied by dose reconstructors to all unmonitored 

CTWs throughout the DOE complex. Guidance is provided for dose reconstructors on the use of this 

adjustment factor.

Examination of the individual DOE sites for internal dose indicated that only the Hanford site required 

adjustment. For the Hanford site, the intake rates in the Hanford coworker study should be multiplied 

by a factor of 2. Guidance is provided for dose reconstructors on the determination of internal dose.
Document No. ORAUT-OTIB-0052 Revision No. 00 Effective Date: 08/31/2006 Page 6 of 35

1.0

Technical Information Bulletins (TIBs) are not official determinations made by the National Institute for 

Occupational Safety and Health (NIOSH) but are rather general working documents that provide

historic background information and guidance to assist in the preparation of dose reconstructions at 

particular sites or categories of sites. They will be revised in the event additional relevant information 

is obtained about the affected site(s). TIBs may be used to assist the NIOSH staff in the completion 

of individual dose reconstructions. 

INTRODUCTION

In this document, the word “facility” is used as a general term for an area, building, or group of 

buildings that served a specific purpose at a site. It does not necessarily connote an “atomic weapons 

employer facility” or a “Department of Energy (DOE) facility” as defined in the Energy Employees 

Occupational Illness Compensation Program Act of 2000 [52 U.S.C. Sections 7385l(5) and (12)]. 

This document presents information that compares doses received by monitored CTWs to doses 

received by all other monitored workers. For the purposes of this document CTWs include, but are 

not limited to, laborers, mechanics, masons, carpenters, electricians, painters, pipe-fitters, insulators, 

boilermakers, sheet-metal workers, operating engineers, and iron workers. 

For the initial comparison on CTW and AMW doses, five DOE sites were selected to represent the 

DOE complex as a whole. These sites (Rocky Flats, Savannah River, Y-12, K-25, and Oak Ridge 

National Laboratory [ORNL]) represent the full spectrum of work (plutonium and uranium processing, 

reactor operations, weapons production, and research laboratory operations) that is associated with 

DOE facilities. Using external dosimetry data from these sites, an investigation and comparison was 

made to determine the relationship between the annual external doses received by CTWs and those 

received by AMWs at the 95th percentile. The annual external doses for CTWs are represented by 

over 200,000 histories, while those for AMWs are represented by over 1,000,000 histories. The 

investigation showed that for the years 1943 to 2005 the annual external doses to the CTWs were

typically bounded by the doses to AMWs. In a more detailed comparison, seven individual DOE sites 

were examined to determine if, at any time, the external dose to the CTWs exceeded that to AMWs. 

There were instances where external doses to CTWs exceeded that of AMWs. This document

presents the data that supports the use of an adjustment factor to account for instances where CTWs 

received higher doses.

As part of the more detailed comparison mentioned above, six of the DOE sites were analyzed to 

determine if, at any time, the bioassay results for CTWs exceeded those of AMWs. It was concluded 

that no adjustment factors were needed for internal dose except Hanford (see Section 8.4). 

For new facility construction, most CTWs were unmonitored because no radioactive material would be 

installed until after the facility was commissioned. However, modifications or major maintenance of 

existing facilities could have involved exposure to radioactive materials and would require monitoring 

of some CTWs. 

Radiation safety regulations (e.g., AEC Manual-0523 and AEC Manual-0524) dating back to the 

1950s required all personnel working in a radiation area to wear a gamma-measuring film-badge. At 

some sites, such as the Nevada Test Site (NTS), all personnel entering the site were required to wear 

a gamma-measuring film-badge in conjunction with their security badge (NTSO-0525). Consequently, 

all persons, including CTWs, working in a radiation area were routinely monitored for exposure to 

external radiation. In most instances, CTWs were not routinely included in the bioassay program of 

the site. However, CTWs were included in the bioassay program when they were suspected of 

having experienced a radioactive material intake.
Document No. ORAUT-OTIB-0052 Revision No. 00 Effective Date: 08/31/2006 Page 7 of 35

While safety regulations and facility-specific radiation protection practices required monitoring of 

radiation workers, it is recognized that under some circumstances some of the CTWs at a facility may 

not have been fully covered or monitored by the radiation protection programs at a site, regardless of 

whether they were employed by the M&O contractor or a construction subcontractor. The reasons for 

partial or altered monitoring of CTWs varied from facility to facility within a site, but it was not 

uncommon to have minimal or alternative monitoring in place during the construction of new facilities 

that were separate from existing facilities. Furthermore, there are instances in which a CTWs dose 

records may be incomplete or unavailable. In cases such as these, the ability to perform a dose 

reconstruction for this CTW is limited by a lack of claimant-specific information and data, so the

claimant is categorized as an unmonitored construction worker. During the development of this 

ORAU Team TIB (OTIB), there was a consistent effort to identify CTWs who were monitored 

regardless of whether they were employed by the M&O contractor or a subcontractor. This document 

provides the basis and guidance for performing dose reconstructions for unmonitored CTWs. 

Although there are limitations and conditions on the data sets used within this OTIB, it is possible to 

separate and compare the external and internal doses received by CTWs and AMWs at a site. These 

comparisons are provided graphically in this OTIB. From these comparisons, which are presented for 

sites that had differing missions, operations, facilities, and radioactive source terms, the relationship 

between doses received by CTWs and AMWs becomes evident. Specifically, the comparisons 

demonstrate that, with some important exceptions and conditions, the dose received by the monitored 

CTWs was typically bounded by the dose received by AMWs on the same site. In order to account for

instances where unmonitored CTWs may have received higher doses than other monitored workers, 

the need for an adjustment factor was identified. The adjustment factor provides a dose 

reconstruction method that is favorable to claimants that have been categorized as unmonitored 

CTWs.

2.0

This document provides guidance for performing dose reconstructions for unmonitored CTWs. For 

the purpose of this document, unmonitored CTWs are defined as workers who worked onsite at any 

time in the site’s history and may have been employed by the M&O contractor at any DOE site. 

These unmonitored CTWs include, but are not limited to, laborers, mechanics, masons, carpenters, 

electricians, painters, pipe-fitters, insulators, boilermakers, sheet-metal workers, operating engineers, 

and iron workers. It should be noted that, in some instances, the prime contractor is not necessarily 

the M&O contractor. For example, in the late 1980s at Hanford, the M&O contractor in the 100 Area 

was Westinghouse while the prime contractor was Kaiser.

PURPOSE

3.0

The guidance developed in this OTIB is limited to dose reconstruction for unmonitored CTWs who: 

SCOPE

1. Were employed by subcontractors or worked directly for the M&O contractor at any DOE site. 

These workers may have been brought onsite by subcontractors to do construction work, but 

may not have been covered under the site’s radiological protection program. 

2. Worked at any time in the site’s history.

3. Do not have a complete exposure history such that for external exposure, they had no external 

monitoring at all or there were gaps of at least a year in their external monitoring or for internal 

exposure, they had no internal monitoring at all or the monitoring they had was inadequate to 

bound their potential exposure.
Document No. ORAUT-OTIB-0052 Revision No. 00 Effective Date: 08/31/2006 Page 8 of 35

4.0

Many sources of data were used to develop this document. These included databases, such as the 

Comprehensive Epidemiologic Data Resource (CEDR), the Center for Epidemiologic Research 

(CER), the Radiation Exposure Monitoring System (REMS), and the Savannah River Site Health 

Protection Annual Radiation Exposure History (HPAREH), as well as annual reports based on AEC 

Form 190. The quality, usability, and accessibility of the data varied, making a standardized 

comparison among sites difficult. For example, some data are available in a modern database as 

official records while others are available only as summaries in centralized compilations. Some data 

have rigorously characterized parametric descriptions, while others are described only by a mean 

value. Sometimes the AMW group includes the CTWs and in others it does not. During the review 

and query of the databases, there was a consistent effort to identify all CTWs regardless of whether 

they were employed by the M&O contractor or a subcontractor.

SOURCES OF DATA

Since the source and degree of data specificity varied among the sites, a brief description of the 

source and treatment of data associated with each DOE site is provided. 

4.1 GENERAL DESCRIPTION OF EXTERNAL DOSE DATA 

External dose data represents the most widely available dosimetry data for radiation workers. Very 

large and well-defined external dosimetry databases exist for most DOE facilities. A number of the 

databases cover or contain data from the entire history of a site.

Data for penetrating dose are contained in various databases some of which have more detail than 

others. Data for AMWs and CTWs are reported for the following sites: Savannah River Site (SRS), 

Y-12, ORNL, K-25, Hanford, Idaho National Laboratory (INL), and Rocky Flats. However, only the 

arithmetic mean of the annual external dose is available for INL and Hanford. 

4.2 GENERAL DESCRIPTION OF THE ADJUSTMENT FACTOR 

The need for an adjustment factor is considered when the annual external penetrating dose for CTWs 

exceeds that for AMWs. If the observed ratio of the annual external penetrating dose for CTWs to 

that of AMWs is less than 1.2, the observed ratios were not included in the site-specific tables. The 

value of 1.2 is a value based on the characteristics of the dosimeter systems and their ability to 

measure dose (NRC 1989). 

The adjustment factor addresses instances in which the annual external penetrating dose for CTWs 

exceeded that for AMWs. Because data from all sites within the DOE complex were not readily

available for analysis and inclusion in this OTIB, a prescribed DOE complex-wide adjustment factor is 

developed and described in Section 7.1. 

4.3 GENERAL DESCRIPTION OF BIOASSAY DATA USED FOR INTERNAL DOSE

Bioassay data are available to cover the majority of the large DOE sites. Bioassay programs are 

typically established based on the need to monitor individuals or groups who had a recognized 

potential for intake of radioactive material. Consequently, bioassay sampling programs or internal 

dose monitoring practices are more highly focused and applied more selectively to a smaller group of 

workers than external monitoring programs. In most instances, CTWs were not included in the routine 

bioassay program of the site. However, CTWs were regularly included in the bioassay program when 

they were suspected of having experienced a radioactive material intake. 
Document No. ORAUT-OTIB-0052 Revision No. 00 Effective Date: 08/31/2006 Page 9 of 35

4.4 GENERAL DESCRIPTION OF NON-PENETRATING DOSE DATA 

Non-penetrating dose data for CTWs and AMWs were available only for the SRS and Rocky Flats 

Plant. 

5.0

Five major DOE sites (SRS, Rocky Flats, Y-12, K-25, and ORNL) were selected to represent the DOE 

complex in an investigation to determine the relationship between the external annual doses received 

by CTWs and AMWs at the 95th percentile. These sites were selected because they represent a 

spectrum of DOE sites where major construction activities took place. A total of over 215,000 

histories for CTWs and over 1,000,000 histories for AMWs were examined. Figure 5-1 is a composite 

graph of the sites and shows the annual external penetrating dose for the time period of 1943 through

2005. Except for the year 1955, Figure 5-1 shows that the external annual dose received by CTWs is 

well bounded by that received by AMWs. In 1955, the external annual dose received by CTWs 

exceeded that received by AMWs by approximately 20%. Based on this observation, seven sites 

were examined individually to determine if, at any time, the external or internal dose to CTWs 

exceeded the dose to AMWs. The seven sites included SRS, Rocky Flats, Y-12, K-25, X-10, INL, and 

Hanford. Hanford and INL were not included with the initial five DOE sites because the dosimetry 

data available for them only addressed the mean of the external dose as opposed to the 95th

percentile.

COMPARISON OF CTW AND AMW DOSES

As indicated in Figure 5-1, doses to CTWs occasionally exceeded doses to AMWs in the 1980s and 

later. A review of the data used in the figure indicated that these exceedances are an artifact caused 

by a large number of AMWs with no measured dose. The large number of AMWs with no measured 

dose led to a smaller value for the 95th-percentile annual dose, making the 95th-percentile annual 

dose for CTWs comparatively larger.

Figure 5-1. 95th-percentile annual penetrating dose for CTWs and AMWs for the DOE complex. 

5.1 SRS PENETRATING DOSE COMPARISON

Information for the period from 1953 through 1999 concerning penetrating doses for SRS CTWs is 

contained in the onsite personnel dosimetry database, HPAREH. The dosimetry data for the SRS 

CTWs in the HPAREH database are identified as Payroll 4 (ROLL 4). This information is subdivided 

95th-Percentile Annual Penetrating Dose for CTWs and AMWs for the DOE Complex 

(CTW = 216,742 Histories; AMW = 1,013,007 Histories)

0

500

1,000

1,500

2,000

2,500

1943 1955 1970 1985 2000

Year

Dose (mrem)

CTW mrem

.AMW mrem
Document No. ORAUT-OTIB-0052 Revision No. 00 Effective Date: 08/31/2006 Page 10 of 35

to identify specific construction trades. However, some trades were not represented or represented 

only a few individuals. As a consequence, conclusions for the period from 1953 through 1999 are 

based only from ROLL 4 data as a whole. 

Dosimetry data include annual deep doses (i.e., external photon radiation) and annual shallow doses 

(i.e., penetrating photons plus non-penetrating radiation). Summary statistics presented in this 

document do not extend post 1999 because, at the time information supporting this document was 

collected, sufficient data beyond that year were not available. 

Figure 5-2. 95th-percentile penetrating dose for SRS. 

Table 5-1 lists the observed ratios that are greater than 1.2 for CTWs and AMWs at SRS. 

Table 5-1. Observed ratios for SRS. 

Year

CTWs AMWs

Observed 

ratios 

(CTWs/AMWs)

Number 

monitored

Number 

with 

measurable 

dose

95thpercentile 

dose

(mrem)

Number 

monitored

Number 

with 

measurable 

dose

95thpercentile 

dose

(mrem)

1962 259 236 1696 3371 3101 1337 1.3

1989 2408 1818 218 15517 8749 170 1.3

1990 2440 1567 190 18494 8503 150 1.3

1991 2202 1104 120 18630 6468 85 1.4

1992 1902 792 95 17780 5016 70 1.4

1997 949 317 83 11344 2410 55 1.5

1998 870 280 71 10750 2210 54 1.3

1999 785 240 62 10365 2159 49 1.3

95th-Percentile Annual Penetrating Dose for SRS

0

500

1000

1500

2000

2500

1953 1957 1961 1965 1969 1973 1977 1981 1985 1989 1993 1997

Year

Dose, mrem

CTW

AMW
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5.2 SRS INTERNAL DOSE COMPARISON

For the SRS, no coworker study has been published and bioassay data are not available 

electronically before about 1990. Records prior to 1990 are stored both on and off the site in paper 

files and on microfiche. During the development of this OTIB, a random sample of records stored on 

the site was obtained for workers with a non-zero external dose recorded in the HPAREH database. 

Equal number of records for CTWs and other workers were requested for individuals employed from 

1955 through 2000. CTWs were identified by ROLL 4 in the HPAREH database.

This sampling produced a data set containing approximately 1,830 plutonium-in-urine measurements, 

one-third of which represented CTWs. According to ORAUT 2005d, prior to 1981 (1988 for special 

samples) the total activity from alpha-emitting isotopes was used to report the amount of plutonium in 

urine, whereas 238Pu and 239+240Pu results were reported separately from 1981 to the present. Since 

this comparison is of the relative activities in the samples, no adjustments were made. All results 

were normalized to 1,400-mL sample size. Results for employees with multiple bioassay samples in 

the same year following a significant intake were removed prior to plotting. This was done so as not 

to bias the results for more typical workers. However, results less than 10 dpm/1,400 mL were 

retained even if there were other samples collected in the same year. Results for three non-CTWs 

and one CTW were removed using this method. 

For non-CTWs, 93% of the results were below the reporting level, while for CTWs, 97% of the results 

were below the reporting level. Only results greater than the reporting level are plotted in Figure 5-3. 

Due to the limited amount of data greater than the reporting level in any given period, no attempt was 

made to calculate 50th-percentile values. Figure 5-3 also includes the typical reporting level 

estimated by a visual inspection of the various periods for comparison. This plot shows that nonCTWs were more likely to have results above the reporting level and more likely to have higher results 

than CTWs.

Figure 5-3. Results of bioassay samples above the reporting level for randomly selected 

CTWs and non-CTWs at SRS. 

Random Sample of Pu-239 Results for SRS

0

1

2

3

4

5

6

7

8

Jan-52 Jan-56 Jan-60 Jan-64 Jan-68 Jan-72 Jan-76 Jan-80 Jan-84 Jan-88 Jan-92 Jan-96 Jan-00

Date

Pu-239 dpm/d

Non-construction

Construction

Reporting Level
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5.3 SRS NON-PENETRATING DOSE COMPARISON

As mentioned in Section 5.1, information for the period from 1953 through 1999 concerning nonpenetrating doses for SRS AMWs and CTWs are contained in the onsite personnel dosimetry 

database, HPAREH. The dosimetry data for the SRS CTWs are identified as Payroll 4 (ROLL 4) in 

the HPAREH database.

The results for the 95th-percentile annual non-penetrating doses appear in Figure 5-4. As is evident 

in Figure 5-4, the annual non-penetrating dose received by the monitored CTWs is adequately 

bounded by the dose received by AMWs at the SRS. 

Figure 5-4. 95th-percentile non-penetrating dose for SRS. 

5.4 ROCKY FLATS PENETRATING DOSE COMPARISON

Construction worker data for Rocky Flats was obtained from the HIS-20 (TM CANBERRA) database. 

This database was the plant’s last dosimetry data tracking system and contains dosimeter results 

from the entire plant history. The CTW data set consisted of workers with the company names 

”Kaiser-Hill Company, L.L.C.” (where the department field contained “construct”), “Kaiser-Hill 

RFETS\10389” (where the department field contained “construct”), “Swinerton & Walberg Company,” 

and “J. A. Jones Construction\3893.” The latter two companies were the construction contractors for 

most of the plant’s history.

Figure 5-5 shows the annual penetrating doses for monitored CTWs and AMWs for the period 1955 

through 2005. 

95th-Percentile Annual Non-Penetrating Dose for SRS

0

1000

2000

3000

4000

5000

6000

7000

1953 1957 1961 1965 1969 1973 1977 1981 1985 1989 1993 1997

Year

Dose, mrem

CTW

AMW
Document No. ORAUT-OTIB-0052 Revision No. 00 Effective Date: 08/31/2006 Page 13 of 35

Figure 5-5. 95th-percentile penetrating dose for Rocky Flats. 

Table 5-2 lists the observed ratios that are greater than 1.2 for CTWs and AMWs at Rocky Flats. 

Table 5-2. Observed ratios for Rocky Flats. 

Year

CTWs AMWs

Observed 

ratios 

(CTWs/AMWs)

Number 

monitored

Number 

with 

measurable 

dose

95thpercentile 

dose

(mrem)

Number 

monitored

Number 

with 

measurable 

dose

95thpercentile 

dose

(mrem)

1991 386 340 755 5641 4951 337 2.2

1994 147 96 242 4839 3198 179 1.4

1995 138 88 455 4130 2502 200 2.3

1996 109 95 393 3454 2761 274 1.4

1998 265 218 592 3470 2036 275 2.2

1999 197 151 359 3655 2138 192 1.9

2000 175 110 278 3576 1256 164 1.7

2001 185 108 202 3443 1518 160 1.3

5.5 ROCKY FLATS INTERNAL DOSE COMPARISON

Construction worker data for Rocky Flats internal dose comparison was obtained from the HIS-20 (TM

CANBERRA) database. Two sets of data containing urine results for the entire history of the site were 

drawn from the database. The first data set consisted of workers with the company names “EG&G 

Rocky Flats Plant,” “Kaiser-Hill Company, L.L.C.” (where the department field did not contain 

“construct”), “Kaiser-Hill RFETS\10389” (where the department field did not contain “construct”), “Safe 

Sites of Colorado, L.L.C.,” and “Rocky Mt Remediation Srv\10528.” This set was selected to 

represent AMWs. 

95th-Percentile Annual Penetrating Dose for Rocky Flats

0

500

1000

1500

2000

2500

3000

3500

4000

4500

5000

1954 1959 1964 1969 1974 1979 1984 1989 1994 1999 2004

Year

Dose, mrem

CTW

AMW
Document No. ORAUT-OTIB-0052 Revision No. 00 Effective Date: 08/31/2006 Page 14 of 35

The second data set consisted of workers with the company names ”Kaiser-Hill Company, L.L.C.” 

(where the department field contained “construct”), “Kaiser-Hill RFETS\10389” (where the department 

field contained “construct”), “Swinerton & Walberg Company,” and “J. A. Jones Construction\3893.” 

The latter two companies were the construction contractors for most of the site’s history. This second 

data set was used to represent CTWs. There were a number of smaller companies that could have 

been added, but the number of urine results would not have increased significantly. 

The data set only included results that were identified in the database as “P,” “Pu239,” or “Pu-239.” 

The results included the activity of all plutonium alphas in the early years, and only Pu-239 and Pu240 activity after analysis by alpha spectroscopy was initiated (see ORAUT 2005a for details). For 

the period from 1953 through 2005, 129,225 results were collected for AMWs and 5,571 results were 

collected for CTWs. 

The Rocky Flats data were analyzed by applying the basic techniques discussed in ORAUT 2005c for 

coworker studies. The data were assumed to be lognormally distributed. Results for highly exposed 

workers who were followed-up with multiple samples in one year were removed from the population, 

so as not to bias the results for more typical workers. However, not all high results were removed. 

This resulted in multiple individuals having their results removed from the AMW data set, but only one 

individual’s results were removed from the CTW data set. The data were analyzed annually for 

AMWs, while the data for CTWs were grouped in intervals of every five years in order to include 

enough data for statistical analysis. Each group was examined, and duplicate and invalid results were 

eliminated. Negative and zero results were replaced by a uniform (linear) distribution ending at the 

MDA value published in the ORAUT 2005a. The results were assumed to represent 24-hr samples or 

were normalized to 24-hr samples by volume in years where volumes were recorded in the database. 

The results were sorted and ranked using the midpoint of the rank. A linear regression analysis of the 

rank versus the natural log of the result was performed and plotted. The R2 value of the regression 

and the plot were inspected to ensure that an adequate fit to the data had been obtained. From the 

regression, the values for the 50th- and the 84th-percentile of the distributions were calculated and 

are shown in Figures 5-6 and 5-7, respectively. As shown in Figures 5-6 and 5-7, the results for 

plutonium in the urine of the CTWs are comparable to results for AMWs who were monitored routinely 

at Rocky Flats. 
Document No. ORAUT-OTIB-0052 Revision No. 00 Effective Date: 08/31/2006 Page 15 of 35

Figure 5-6. 50th-percentile plutonium in urine for Rocky Flats. 

50th-Percentile Plutonium in Urine Results for Rocky Flats

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

1953 1957 1961 1965 1969 1973 1977 1981 1985 1989 1993 1997 2001 2005

Year

Pu-239 dpm/d

CTW

AMW
Document No. ORAUT-OTIB-0052 Revision No. 00 Effective Date: 08/31/2006 Page 16 of 35

Figure 5-7. 84th-percentile plutonium in urine for Rocky Flats. 

5.6 ROCKY FLATS NON-PENETRATING DOSE COMPARISON

CTW and AMW data for Rocky Flats was obtained from the HIS-20 database using the criteria 

discussed under the penetrating dose section.

The results for the 95th-percentile annual non-penetrating doses appear in Figure 5-8 and show that 

at the 95th percentile, the annual non-penetrating dose received by the monitored CTWs at the Rocky 

Flats Plant is adequately bounded by the dose received by AMWs at the Rocky Flats Plant.

84th-Percentile Plutonium in Urine Results for Rocky Flats 

0.00

0.20

0.50

0.60

0.80

1.00

1.20

1.50

1953 1957 1961 1965 1969 1973 1977 1981 1985 1989 1993 1997 2001 2005

Year

Pu-239 dpm/dCTW

AMW
Document No. ORAUT-OTIB-0052 Revision No. 00 Effective Date: 08/31/2006 Page 17 of 35

Figure 5-8. 95th-percentile non-penetrating dose for Rocky Flats. 

5.7 Y-12 PENETRATING DOSE COMPARISON

External dose data for Oak Ridge Y-12 are taken from the Oak Ridge Institute for Science and 

Education (ORISE) CER database (ORAUT 2005c). The records in this database include external 

radiation exposure measurement results pertinent to the health and safety monitoring of employees 

and contract employees of the DOE and its predecessor organizations. Data on CTWs were obtained 

using a query designed to extract job titles associated with construction work. Data on any worker 

with a job title that included any of the following words or portions of words were included in the CTW 

data set: craft, carp, equip, heavy, plumb, pipef, millw, ship, skill, laborer, black, linem, boil, brick, tile, 

metal w, metal, crane, paint, mason, sheet, maint, truck, weld, rigger, or iron.

Figure 5-9 shows the data for 95th-percentile penetrating dose for both monitored CTWs and AMWs 

for the period from 1950 through 1988. As shown in Figure 5-9, the 95th-percentile annual 

penetrating dose received by the monitored CTWs at Y-12 is adequately bounded by the doses 

received by AMWs at Y-12. 

95th-Percentile Non-Penetrating Dose for Rocky Flats

0

1000

2000

3000

4000

5000

6000

1955 1959 1965 1969 1975 1979 1985 1989 1995 1999 2005

Year

Dose, mrem

CTW

AMW
Document No. ORAUT-OTIB-0052 Revision No. 00 Effective Date: 08/31/2006 Page 18 of 35

Figure 5-9. 95th-percentile penetrating dose for Y-12. 

5.8 Y-12 INTERNAL DOSE COMPARISON

Bioassay results for uranium in urine samples for personnel who worked at Oak Ridge Y-12 are taken 

from the ORISE CER database (ORAUT 2005c). Data on CTWs was obtained using a query 

designed to extract job titles associated with construction work. (See Section 5.7 for details on the 

data query.) 

Data generated by the query were reviewed to determine if a singular sample result or results 

associated with unusual incidents were unduly influencing the overall data comparison. Such data 

are characterized as outliers and these results were removed from the data set in order to improve the 

value of the data comparison. 

The 50th and 84th percentile of these bioassay results are shown by year in Figures 5-10 and 5-11, 

respectively. In general, there is good agreement between the sample results for CTWs and AMWs. 

The graph represents the 50th-percentile of uranium in urine for Y-12. 

Y-12 95th-Percentile External Dose

0

200

400

600

800

1000

1200

1950 1955 1960 1965 1970 1975 1980 1985 1990

Dose, mrem

CTW

AMW
Document No. ORAUT-OTIB-0052 Revision No. 00 Effective Date: 08/31/2006 Page 19 of 35

Figure 5-10. 50th-percentile uranium in urine for Y-12. 

Figure 5-11. 84th-percentile uranium in urine for Y-12. 

0

2

4

6

8

10

12

14

16

18

1945 1950 1955 1960 1965 1970 1975 1980 1985 1990

AMW

dpm/d

CTW

Y-12 50th-Percentile Uranium in Urine

Y-12 84th-Percentile Uranium in Urine

0

10

20

30

40

50

60

1945 1950 1955 1960 1965 1970 1975 1980 1985 1990

dpm/d

AMW

CTW
Document No. ORAUT-OTIB-0052 Revision No. 00 Effective Date: 08/31/2006 Page 20 of 35

5.9 K-25 PENETRATING DOSE COMPARISON

External dose data for K-25 are taken from the ORISE CER database (ORAUT 2005c). The records 

in this database include external radiation exposure measurement results pertinent to the health and 

safety monitoring of employees and contract employees of the DOE and its predecessor 

organizations. Data on CTWs were obtained using a query designed to extract job titles associated 

with construction work. (See Section 5.7 for details on the data query.) 

Figure 5-12 shows the data for the 95th-percentile penetrating dose for both monitored CTWs and 

AMWs for the period beginning in 1943 and ending in 1988. Figure 5-12 shows that the annual 

penetrating dose received by the monitored CTWs at K-25 is adequately bounded by the doses 

received by AMWs at K-25. 

Figure 5-12. 95th-percentile penetrating dose for K-25. 

5.10 K-25 INTERNAL DOSE COMPARISON

Bioassay results for uranium in urine samples for personnel who worked at K-25 are taken from the

ORISE CER database (ORAUT 2005c). Data on CTWs were obtained using a query designed to 

extract job titles associated with construction work. (See Section 5.7 for details on the data query.) 

The 50th and 84th percentile of these bioassay results are shown in Figures 5-13 and 5-14, 

respectively. In general, there is good agreement between the sample results for CTWs and AMWs. 

K-25 95th-Percentile External Dose

0

100

200

300

400

500

600

700

800

1945 1950 1955 1960 1965 1970 1975 1980 1985 1990

Dose, mrem

CTW

AMW
Document No. ORAUT-OTIB-0052 Revision No. 00 Effective Date: 08/31/2006 Page 21 of 35

Figure 5-13. 50th-percentile uranium in urine for K-25. 

Figure 5-14. 84th-percentile uranium in urine for K-25. 

K-25 50th-Percentile Uranium in Urine Results

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1945 1950 1955 1960 1965 1970 1975 1980 1985 1990

alpha dpm/100 mL

CTW

AMW

K-25 84th-Percentile Uranium in Urine Results

0

0.5

1

1.5

2

2.5

3

3.5

1945 1950 1955 1960 1965 1970 1975 1980 1985 1990

alpha dpm/100 mL

CTW

AMW
Document No. ORAUT-OTIB-0052 Revision No. 00 Effective Date: 08/31/2006 Page 22 of 35

5.11 ORNL PENETRATING DOSE COMPARISON

External dose data for ORNL are taken from the ORISE CER database (ORAUT 2005c). The records 

in this database include external radiation exposure measurement results pertinent to the health and 

safety monitoring of employees and contract employees of the DOE and its predecessor 

organizations. Data on CTWs were obtained using a query designed to extract job titles associated 

with construction work. (See Section 5.7 for details on the data query.) 

Figure 5-15 shows the 95th-percentile annual penetrating dose for both monitored CTWs and AMWs 

at the ORNL for the period from 1943 through 1988.

 

Figure 5-15. 95th-percentile penetrating dose for ORNL. 

Table 5-3 lists the observed ratios that are greater than 1.2 for CTWs and AMWs at ORNL. 

ORNL 95th-Percentile External Dose

0

500

1000

1500

2000

2500

3000

1940 1950 1960 1970 1980 1990

Dose, mrem

CTW

AMW
Document No. ORAUT-OTIB-0052 Revision No. 00 Effective Date: 08/31/2006 Page 23 of 35

Table 5-3. Observed ratios for ORNL. 

Year

CTWs AMWs

Observed 

ratios

(CTWs/AMWs)

Number 

monitored

Number 

with 

measurable 

dose

95thpercentile 

dose

(mrem)

Number 

monitored

Number 

with 

measurable 

dose

95thpercentile 

dose

(mrem)

1955 604 470 2231 3931 2193 1650 1.4

1957 623 608 2515 4277 3734 1750 1.4

1959 704 696 2058 4698 4350 1636 1.3

1960 682 618 1480 4793 3427 1087 1.4

1961 695 627 1096 4779 3785 810 1.4

1962 722 696 1200 4953 4591 940 1.3

1963 750 681 1015 5174 4243 803 1.3

1965 817 551 864 5646 2930 680 1.3

1966 822 582 1040 5972 2765 680 1.5

1967 878 585 1163 6252 2657 780 1.5

1968 852 542 814 5981 2303 610 1.3

1969 808 403 670 5809 1754 516 1.3

1971 725 318 558 5154 1428 390 1.4

1972 691 289 645 5097 1203 422 1.5

1973 661 315 620 4984 1336 400 1.6

1974 739 363 421 5407 1611 250 1.7

1975 767 283 457 5788 1129 290 1.6

1976 784 268 378 6123 1169 210 1.8

1977 804 228 250 6434 1042 160 1.6

1978 798 206 333 6660 899 160 2.1

1979 776 209 440 6357 915 182 2.4

1980 754 130 214 6480 635 70 3.1

1981 723 170 409 6313 606 150 2.7

1982 667 119 247 5782 480 130 1.9

1983 608 146 436 5562 489 170 2.6

1984 602 144 339 5610 522 150 2.3

1985 585 139 288 5641 502 130 2.2

1986 514 94 193 4998 430 100 1.9

1987 482 92 138 4894 382 70 2.0

1988 484 91 134 5102 372 50 2.7

5.12 ORNL INTERNAL DOSE COMPARISON

Bioassay results for urine samples for personnel who worked at Oak Ridge National Laboratory are 

taken from the Oak Ridge Institute for Science and Education (ORISE) Center for Epidemiology 

Research (CER) database (ORAUT 2005c). Data on CTWs were obtained using a query designed to 

extract job titles associated with construction work. (See Section 5.7 for details on the data query.) 

From 1951 through 1964 plutonium in urine was measured as gross alpha. From 1965 to 1987 the 

analysis method became specific for plutonium. The 50th percentile and 84th percentile of these 

bioassay results are shown by year in Figures 5-16 and 5-17, respectively. 

Uranium in urine was also measured at ORNL. Figures 5-18 and 5-19 show the results of the median 

and 84th percentile for this analysis, respectively. 

In general, there is good agreement between the CTW and AMW data for both plutonium and uranium 

at the 50th and 84th percentile.
Document No. ORAUT-OTIB-0052 Revision No. 00 Effective Date: 08/31/2006 Page 24 of 35

Figure 5-16. 50th-percentile plutonium in urine for ORNL. 

Figure 5-17. 84th-percentile plutonium in urine for ORNL. 

ORNL 50th-Percentile Plutonium in Urine Results

0

0.05

0.1

0.15

0.2

0.25

1945 1950 1955 1960 1965 1970 1975 1980 1985 1990

dpm/d

CTW

AMW

ORNL 84th-Percentile Plutonium in Urine Results

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

1945 1950 1955 1960 1965 1970 1975 1980 1985 1990

dpm/d

CTW

AMW
Document No. ORAUT-OTIB-0052 Revision No. 00 Effective Date: 08/31/2006 Page 25 of 35

Figure 5-18. 50th-percentile uranium in urine for ORNL. 

Figure 5-19. 84th-percentile uranium in urine for ORNL. 

ORNL 50th-Percentile Uranium in Urine

0

0.5

1

1.5

2

2.5

3

3.5

4

1945 1950 1955 1960 1965 1970 1975 1980 1985 1990

dpm/100 ml

AMW

CTW

ORNL 84th-Percentile Uranium in Urine

0

1

2

3

4

5

6

7

8

9

10

1945 1950 1955 1960 1965 1970 1975 1980 1985 1990

dpm/100 ml

AMW

CTW
Document No. ORAUT-OTIB-0052 Revision No. 00 Effective Date: 08/31/2006 Page 26 of 35

5.13 INL PENETRATING DOSE COMPARISON

Penetrating doses for INL are presented in Figure 5-20 for the period beginning in 1974 and ending in 

2005. Radiation exposure data prior to 1974 was not available. However, in “Occupational Radiation 

Exposure History of Idaho Field Office Operations at the INEL,” John R. Horan and Julie B. Braun 

discuss construction worker exposures during the early period: “[Construction personnel] exposures 

were negligible during the first decade and were almost all below 0.5 rem/yr thereafter.” 

Figure 5-20. Mean value for penetrating dose for INL. 

Table 5-4 lists the observed ratios that are greater than 1.2 for CTWs and AMWs at INL. 

Average Annual Penetrating Dose for INL

0

100

200

300

400

500

600

700

1974 1976 1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006

Dose, mrem

CTW

AMW
Document No. ORAUT-OTIB-0052 Revision No. 00 Effective Date: 08/31/2006 Page 27 of 35

Table 5-4. Observed ratios for INL. 

Year

CTWs AMWs

Observed 

ratios

(CTWs/AMWs)

Number 

monitored

Number 

with 

measurable 

dose

Average 

dose

(mrem)

Number 

monitored

Number 

with 

measurable 

dose

Average 

dose

(mrem)

1979 953 396 461 5097 2407 360 1.3

1986 1321 536 479 5956 1994 296 1.6

1988 463 311 186 4813 1751 135 1.4

1989 416 263 317 5385 1829 172 1.8

1990 430 223 260 6033 1960 177 1.5

1992 427 157 134 5889 1007 87 1.5

1994 418 211 180 6006 1659 143 1.3

1998 384 104 146 5075 743 87 1.7

1999 565 95 101 8885 729 66 1.5

2003 422 155 70 4682 1141 56 1.3

2004 428 186 109 3853 1471 74 1.5

5.14 INL INTERNAL AND NON-PENETRATING DOSE COMPARISON

Data for internal exposures for workers at the INL was not available. However, Horan and Braun’s 

report briefly discusses non-penetrating and internal exposures, and indicates that they were 

traditionally negligible: “Non-penetrating radiation exposure to the skin from soft X-rays or Beta 

particles were also not included along with irradiation by internally deposited radionuclides since 

historically they have been extremely rare events and as a result a very minor contributor to the 

effective dose.” 

6.0

Hanford was the first facility to generate and separate special nuclear material for weapons 

production. As such, Hanford can be viewed as a type of R&D facility where chemical separation and 

reactor process were one-of-a-kind experimental prototypes. As the research/information base grew 

and new chemical processes were developed, contaminated facilities were retrofitted or replaced to 

accommodate the new processes. It is postulated that this practice was responsible for elevated 

doses to the CTWs. Consequently, adjustment factors are developed to augment the dose to the 

CTWs during specific time periods.

HANFORD SITE

6.1 HANFORD SITE PENETRATING DOSE COMPARISON

The data were extracted from various sources including a scientific paper (Keene 1960), a series of 

annual reports based on AEC Form 190 (Heffelbower 1963–1970), a series of letter reports (Annual 

Radiation Exposure Summary to USAEC from the Manager, Radiation Protection, Hanford 

Laboratory), the annual summary reports of radiation exposures (see Summary Annual Reports in the 

References Section), the REMS database (DOE 2006), and a Hanford coworker study of external 

dose (ORAUT 2005e). 

The data from Keene (1960) for the period from 1944 through1959 consists of the fourteen job 

categories that have the highest accumulated dose for that time period. Five of the job categories are 

assumed to represent CTWs. The number of workers, the average service in years, and the average 

dose is provided for each job category. From these data, average doses per year are calculated for 

CTWs and AMWs. Starting in 1960, reports generally present the annual dose in ranges (e.g., 0 – 1 

rem, 1 – 2 rem, etc.). In those instances, the value of the midpoint of each range was used to 

calculate the average dose. 
Document No. ORAUT-OTIB-0052 Revision No. 00 Effective Date: 08/31/2006 Page 28 of 35

For the period from 1991 through 2005 the doses for the CTWs and AMWs are determined using the 

REMS database. The annual collective penetrating dose is determined by subtracting the collective 

committed effective dose equivalent (if any) from the collective total effective dose equivalent (personmrem). The average penetrating dose is determined by dividing the annual dose by the number of 

workers with measured dose.

For the CTWs, the annual dose is determined by summing the annual doses for the REMS 

“Construction” and “Laborer” labor categories. The workers in the REMS “Laborers” category are 

segregated by the reporting organizations. The annual doses reported by the organizations that are 

not the M&O contractor are summed and added to the annual dose for the REMS “Construction”

category. Doses in the range less than 100 mrem are not included. This eliminates most visitors and 

administrative personnel from the REMS data. The average annual dose for CTWs is determined by 

dividing the annual dose for the “Laborers” and the “Construction” categories by the number of 

workers in those categories with measurable dose. 

For AMWs, the average annual dose is determined by summing the annual doses in the REMS “All” 

category (i.e., management, scientists, service, etc.) and dividing that sum by the sum of workers who 

had measured dose in the “All” category.

Penetrating doses for monitored CTWs and AMWs are shown in Figure 6-1. Table 6-1 lists the 

observed ratios that are greater than 1.2 for CTWs and AMWs at Hanford. As indicated in the graph 

and table, the doses for the CTWs and AMWs are comparable with two exceptions: the period from

1968 through 1981 and the period from 1985 through 1988. These time periods generally coincide 

with the increased work activity associated with the shut-down of the production reactors from 1968 

through 1981 and the restart of the Purex Plant from 1985 through 1988. Due to the nature and time 

period for this work, it is unlikely that any unmonitored CTWs were involved. Therefore, these data 

points were not considered as representative and meaningful for the purposes of this OTIB. 

6.2 HANFORD SITE INTERNAL DOSE COMPARISON

An internal dosimetry coworker study that includes both CTWs and AMWs has been published for the 

Hanford site (ORAUT 2006). The database used to develop the coworker study had limited 

descriptive information for workers such that data for CTWs cannot be identified before 1965. For the 

period from 1965 through 1978, plutonium data for CTWs is identified by a company-field in the 

database. These data were processed in accordance with ORAUT 2006 to develop datasets for 

CTWs. For the period from 1965 through 1975, the datasets were analyzed annually as opposed to 

quarterly due to their small size. For the period from 1975 through 1978, the datasets were grouped 

and analyzed together. (See ORAUT 2006 for additional details.) 

For the period from 1978 through 1989, the plutonium data for CTWs is very limited and appears to 

consist mainly of special samples following incidents. Where it was appropriate, duplicates and data 

for highly exposed individuals were removed since these data are not truly representative of CTWs as 

a group. However, no attempt was made to remove all special (follow-up) results. This approach in 

reviewing and qualifying the data recognized that small intakes were essentially a part of routine 

operations. As in ORAUT (2006), results with volumes less than 400 mL were not used in the 

statistics. 
Document No. ORAUT-OTIB-0052 Revision No. 00 Effective Date: 08/31/2006 Page 29 of 35

Figure 6-1. Average annual penetrating dose for Hanford. 

The results were assumed to be lognormally distributed and were analyzed using the basic 

techniques for coworker studies described in ORAUT-OTIB-0019, Analysis of Coworker Data for 

Internal Dose Assignment (ORAUT 2005d). The resultant 50th- and 84th-percentile values were 

multiplied by 0.835 to convert total plutonium alpha to 239Pu activity, assuming 10-yr-aged fuel-grade 

plutonium. This conversion was necessary to make the results directly comparable to the values in 

ORAUT (2006). 

The Hanford data-forms included a field to enter the reason for the bioassay (“reason code”). 

Unfortunately, this field was not used consistently over the years in question. Nor was it reported in 

the Hanford coworker study. It appears that a high percentage of special bioassay samples may have 

biased the data for the years where the data for CTWs is higher than the data for AMWs. The 

maximum difference between the CTW data and the AMW data was about a factor of two, but, as is 

evident in Figures 6-2 and 6-3, the difference varied from year to year. It appears that applying a 

factor of two to the intake rates in the Hanford coworker study is favorable to construction worker 

claimants.

The results of the analysis and the data from ORAUT (2006) appear in Figures 6-2 and 6-3.

Hanford Average Penetrating Dose

0

200

400

600

800

1000

1200

1955-1959 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005

Dose (mrem)

CTW

AMW
Document No. ORAUT-OTIB-0052 Revision No. 00 Effective Date: 08/31/2006 Page 30 of 35

Table 6-1. Observed ratios and average penetrating dose for CTWs and AMWs at Hanford. 

Year

CTWs AMWs

Observed ratios

(CTWs/AMWs)

Number 

monitored

Number with

measurable dose

Average 

dose

(mrem)

Number with

measurable dose

Average 

dose

(mrem)

1970 1,365 1,158 1,020 10,053 702 1.5

1975 408 402 1,036 3,578 745 1.4

1978 1,917 1,864 467 6,882 372 1.3

1979 1,915 1,770 422 7,517 332 1.3

1980 1,585 1,437 537 6,917 320 1.7

1981 1,542 1,386 479 7,182 286 1.7

1985 1,642 808 660 5,954 427 1.5

1987 1,804 1,225 793 6,697 393 2.0

1990 934 428 181 3,753 119 1.5

1993 1,351 556 196 3,147 133 1.5

1994 1,696 567 222 3,166 150 1.5

1997 1,022 366 393 2,058 284 1.4

1960-1973 from various Hanford letter reports

1975-1990 from DOE annual dose reports

1991-2005 from the DOE REMS database

Figure 6-2. 50th-percentile for Pu-239 in urine for Hanford. 

50th-Percentile Pu-239 Results for Hanford

0

0.005

0.01

0.015

0.02

0.025

1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978

Year

Pu-239 dpm/d

All Workers

Construction
Document No. ORAUT-OTIB-0052 Revision No. 00 Effective Date: 08/31/2006 Page 31 of 35

Figure 6-3. 84th-percentile for Pu-239 in urine for Hanford. 

7.0

Comparisons between the doses received by CTWs and AMWs have shown that, with some 

exceptions and conditions, the dose received by the monitored CTWs was usually bounded by the 

dose received by AMWs on the same site.

CONCLUSIONS

This relationship between the doses received by CTWs and AMWs can be combined with the premise 

that the nature of the construction work (e.g., carpentry, masonry, pipe-fitting, etc.) performed by 

unmonitored CTWs was not significantly different (from a radiation protection perspective) than the 

construction work activity performed by monitored CTWs. Doses to monitored CTWs can therefore 

serve as an acceptable surrogate for doses to unmonitored CTWs. 

An analysis of the specific DOE sites identified specific years that CTWs doses exceeded AMWs 

doses. To address these instances, an adjustment factor is needed.

7.1 PRESCRIBED EXTERNAL ADJUSTMENT FACTOR FOR ALL DOE FACILITIES

Due to limitations on the availability and specificity of CTW and AMW data from other DOE sites, this 

OTIB presents a limited analysis and comparison of CTW and AMW data. In order to reconcile this 

limited data analysis with the site-specific comparisons that indicate that external doses to CTWs 

occasionally exceeded doses to AMWs, a prescribed adjustment factor is needed for dose 

reconstructions for unmonitored CTWs. 

The prescribed external dose adjustment factor was based on consideration of the relative magnitude 

and trend in CTW and AMW doses shown in Figure 5-1, specifically: 

84th-Percentile Pu-239 Results for Hanford

0.00

0.02

0.04

0.06

0.08

0.10

0.12

1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978

Year

Pu-239 dpm/d

CTW

AMW
Document No. ORAUT-OTIB-0052 Revision No. 00 Effective Date: 08/31/2006 Page 32 of 35

• CTW doses occasionally exceeded AMW doses during the late 1980s and 1990s. 

However, this reflects work within the DOE complex when radiation protection programs 

were well established and nearly all potentially exposed workers were monitored. 

Furthermore, these occasional exceedances have been identified as artifacts caused by a 

large number of AMWs with no measurable dose.

• CTW doses were significantly lower than AMW doses for an extended period that started 

in 1961. This indicates that the adjustment factor should be based on instances where 

CTW doses exceeded AMW doses prior to 1961. 

• The values for pre-1961 adjustment factors range from 1.3 to 1.4. 

• The maximum value of 1.4 was selected as the prescribed favorable to claimant external 

dose adjustment factor (i.e., dose multiplier) for all DOE facilities for all years. 

8.0

8.1 LIMITATIONS

LIMITATIONS AND APPLICATIONS

The application of the conclusions and adjustment factors derived in this document are limited to dose 

reconstructions for unmonitored construction workers at sites with applicable coworker data or an 

acceptable method for dose reconstruction for unmonitored workers. 

8.2 GUIDANCE ON THE DETERMINATION OF PENETRATING DOSE FOR 

UNMONITORED CTWS 

Use the guidance in ORAUT-OTIB-0020 to assign a penetrating dose that is favorable to unmonitored 

CTWs. The value of the measured dose 95th percentile should be used unless there is compelling 

evidence to use another coworker percentile value. Apply an adjustment factor of 1.4 to the

appropriate percentile of the measured coworker data for the site, plus the assigned coworker missed 

dose, to determine the total assigned penetrating dose that is favorable to unmonitored CTWs. 

For non-prime CTWs, the dose reconstruction method should use applicable coworker doses and the 

adjustment factor. For any prime CTWs that have unmonitored periods where they should have been 

monitored, the dose reconstruction method should use coworker doses with the adjustment factor of 

1.4.

8.3 GUIDANCE ON THE DETERMINATION OF NON-PENETRATING DOSE FOR

UNMONITORED CTWS 

Based on the comparison from SRS and Rocky Flats, the 95th percentiles for the annual nonpenetrating doses in the other coworker studies may be used to assign annual non-penetrating dose 

to those CTWs whose dose history is either unavailable or incomplete unless there is compelling 

evidence to use another coworker percentile value. 

Due to a lack of data, it was not possible to provide a comparison of non-penetrating doses from 

Hanford. Dose reconstructors should not apply any adjustment factors for non-penetrating dose.
Document No. ORAUT-OTIB-0052 Revision No. 00 Effective Date: 08/31/2006 Page 33 of 35

8.4 GUIDANCE ON THE DETERMINATION OF INTERNAL DOSE

For Hanford dose reconstructions covered by this OTIB, the intake rates in the Hanford coworker 

document should be multiplied by a factor of two. 

For all other sites, the internal dose should be determined using the same method that is applied to all 

other workers. If coworker data studies are available for a site, the 50th percentile should be used 

with the appropriate GSD unless there is compelling evidence to use another coworker percentile 

value.

8.5 GUIDANCE ON THE DETERMINATION OF OCCUPATIONAL MEDICAL DOSE

Dose reconstructors should review the claim file for X-ray records.

1. If there are X-ray records in the file, the dose reconstructor should use the Technical Basis 

Document (TBD) for the site where the worker performed the work to assign X-ray dose. For 

example, a worker who worked for Atkinson/Jones at Hanford could have X-ray records in 

his/her file. The X-ray dose should be assigned from the Hanford TBD organ dose tables.

2. For sites where “X-ray records do not exist” is indicated and there are in fact no-X-ray records 

in the file or for sites that are not currently including X-ray records, such as Y-12 and INL, the 

dose reconstructor should use the TBD for the site where the worker performed the work to 

assign the frequency or X-ray procedures that are clearly not a result of work-related injury. 

However, since these procedures may have been performed off-site, the assigned organ 

doses should come from Dose Reconstruction from Occupationally Related Diagnostic X-Ray 

Procedures (ORAUT 2005f). All X-ray procedures in this category should be assumed to be 

standard X-rays (not PFG) since PFG was an X-ray technique suitable to screening large 

groups of people at one time. Assuming the X-rays were performed off-site at a local clinic or 

hospital, it is unlikely that this screening occurred en masse with PFG. 
Document No. ORAUT-OTIB-0052 Revision No. 00 Effective Date: 08/31/2006 Page 34 of 35

REFERENCES

Cited References

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Mason & Hanger-Silas Mason Company, Burlington, Iowa. [SRDB Ref ID: 828]

Horan, J. R. and J. B. Braun, 1993, Occupational Radiation Exposure History of Idaho Field Office 

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Keene, A. R., 1960, Analysis of the Distribution of Externally Received Radiation at Hanford, 1944-

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Ridge, Tennessee, June 29.

ORAUT (Oak Ridge Associated Universities Team), 2005c, Analysis of Coworker Data for Internal 

Dose Assignment, ORAUT-OTIB-0019, Rev. 01, Oak Ridge, Tennessee, October 7.

ORAUT (Oak Ridge Associated Universities Team), 2005d, Savannah River Site, ORAUT-TKBS0003, Rev. 03, Oak Ridge, Tennessee, April 5.

ORAUT (Oak Ridge Associated Universities Team), 2005e, Use of Coworker Dosimetry Data for 

Hanford, ORAUT-OTIB-0030, Rev. 00, Oak Ridge, Tennessee, March 23. 

ORAUT (Oak Ridge Associated Universities Team), 2005f, Dose Reconstruction from Occupationally 

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ORAUT (Oak Ridge Associated Universities Team), 2006, Internal Dosimetry Coworker Data for the 

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Document No. ORAUT-OTIB-0052 Revision No. 00 Effective Date: 08/31/2006 Page 35 of 35

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DOE (U.S. Department of Energy), 1989, Twentieth Annual Report, Radiation Exposures for DOE and 

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DOE (U.S. Department of Energy), 1990, Twenty-First Annual Report, Radiation Exposures for DOE 

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